1. Field of the Invention
The present invention relates to a camera module for a mobile apparatus, and more particularly to a camera module with a hinge spring which can more stably support a lens barrel moving in a vertical direction for image focusing and is molded using a lightweight and elastic resin.
2. Description of the Related Art
Recently, mobile apparatuses, such as cellular phones and notebook computers, are generally equipped with camera modules in which imaging devices, such as charge coupled device (CCD) image sensors and complementary metal oxide semiconductor (CMOS) image sensors, are mounted. As such camera modules provided in the mobile apparatuses have come to have higher pixels and performance, mobile apparatuses have gained a high-quality camera function, enabling them to compete with high-end digital cameras. The camera module of the mobile apparatus generally uses a voice coil motor (VCM) actuator or a Piezo actuator for image focusing.
In the VCM actuator, automatic focusing is performed by moving a lens barrel equipped with lenses in a vertical direction by electromagnetic force generated by reciprocal actions between a magnetic field of a permanent magnet and an electric field generated by current flowing through a coil. On the other hand, in the Piezo actuator, the automatic focusing is performed by moving a lens barrel in a vertical direction by Piezo elements vibrating with predetermined amplitude when current is applied. An example of the camera module with such an automatic focusing actuator is disclosed in KR 10-2008-0039239 published on May 7, 2008 (see FIG. 1 and FIG. 2), and such known lens actuators are shown in FIG. 6 and FIG. 7 of this specification.
As shown in FIG. 6 and FIG. 7, in the known lens actuator disclosed in KR 10-2008-0039239, a carrier 11 having lenses therein is supported by two leaf springs 14 and 15 so that the carrier 11 can move in an optical axis direction.
That is, in the known lens actuator, the carrier 11 is elastically supported by upper and lower leaf springs 14 and 15 which are thin metal plate members made of steel or copper alloy so that the carrier 11 can move up and down in an optical axis direction thanks to magnet and coil. Accordingly, the carrier 11 is disposed at a predetermined position in a casing 13.
However, the known lens actuator having the above-mentioned structure is disadvantageous in that it needs to be manufactured using a thin leaf spring of a metal so that the carrier can move in a vertical direction. However, it is difficult to manufacture the leaf spring having a shape shown in FIG. 7. That is, when manufacturing the leaf spring by press-processing metal, it is difficult to precisely process a portion of the leaf spring, which is likely to deform owing to the movement of the carrier, and therefore the leaf springs may have variance in their elasticity.
Further, since the leaf springs are made of a metal, the known lens actuator is expensive, the number of manufacturing processes is large, and the manufacturing time is long.